The One With The Mugging - S9-E15
Continuity mistake: When Chandler, Rachel and Monica are discussing the sneakers, Rachel is holding a water bottle. In a close up shot it has the cap on it, in the next far shot it is on the table without a cap. (00:15:30)
The One With The Fertility Test - S9-E21
Continuity mistake: When Charlie tells Ross about the Met, Ross goes sitting next to her, and his hands are empty when he says: 'Joey really knows his art, huh?' When Charlie says: 'Not so much' Ross suddenly holds a book in his hands. Then, when the shot changes, the book is gone again. It keeps (dis)appearing during the scene. (00:20:35)
The One With Christmas in Tulsa - S9-E10
Continuity mistake: When the group notice that it's snowing outside, external shots show a lot more snow than the internal shots. (00:19:20)
The One Where Emma Cries - S9-E2
Continuity mistake: When Joey is seen apologising in front of the hospital room door, we can see a pink wall only about 2 metres behind him. However, in every scene before that which features the door, we can see it leads out to a large open area.
The One With The Blind Dates - S9-E14
Continuity mistake: When Rachel is at her blind date, and Steve tells her that he's selling T-Shirts now, Rachel's arms are on the table, but then the camera cuts to her, and she has her arms crossed. (00:12:00)
The One With the Pediatrician - S9-E3
Continuity mistake: In the scene where Phoebe asks Mike to prove that he plays piano, his arm goes from resting on the couch to on his lap from one shot to the next. After Phoebe tells him "You are really good," his left arm is resting on the couch. But in the next shot when Phoebe continues talking, his arm is resting on his lap.
The One With The Lottery - S9-E18
Continuity mistake: After he gets the job Chandler sits on the couch pretending to read a magazine and Joey drops a piece of paper that materialises in his right hand in between shots. (00:19:40)
The One With the Male Nanny - S9-E6
Continuity mistake: When Phoebe is trying to explain to David that she really cares about Mike the door behind David is closed, but when Mike walks in that door is wide open, and it remains open until it's suddenly closed when Mike warns David that if he ever goes to Minsk he'd better watch out.
The One With Rachel's Other Sister - S9-E8
Continuity mistake: When Chandler puts the box of china down on the chair, the lid of the box is shut, but a bit later the box is wide open.
The One With Phoebe's Rats - S9-E12
Continuity mistake: When Gavin and Rachel are in Rachel's office, in some shots Gavin is wearing a wedding ring. (00:03:43)
The One In Barbados, part 2 - S9-E24
Continuity mistake: As Mike and Monica are playing ping-ping, two people playing checkers magically materialize behind Monica. One second they're not there and the next second they are. (00:12:25)
The One Where Monica Sings - S9-E13
Continuity mistake: When Phoebe, Monica and Rachel are talking in the coffee house, a waitress walks by and in the next shot when the camera focuses on Monica, and comes back to Rachel, the waitress walks by again. (00:05:00)
The One With the Pediatrician - S9-E3
Continuity mistake: Joey's date eats the two olives from her martini, but in the next shot she suddenly has the two olives in her drink again.
The One With Phoebe's Rats - S9-E12
Continuity mistake: When Monica goes to Rachel's office and invites Gavin to Rachel's birthday party Rachel gets up and goes to the door exclaiming "why did you invite him, I hate that guy." She has nothing in her hand when she gets up from her desk; but at the very end of the scene when she tells Monica to be quiet, she's got a pen in her hand for one shot. (00:12:45)
The One With The Memorial Service - S9-E17
Continuity mistake: After Phoebe kisses Mike in her apartment, Mikes friend rushes in and discovers them. As soon as the shot widens, Mike's hand moves from being behind Phoebes head to his lap. (00:17:35)
The One With Phoebe's Rats - S9-E12
Continuity mistake: At the party, when Monica and Rachel are talking about Gavin, Rachel has a napkin in her hand at one shot, the shot changes and the napkin is replaced by a drink. (00:13:20)
The One With Phoebe's Rats - S9-E12
Continuity mistake: Phoebe is sitting on her couch talking with Mike near the end of the episode. She puts the box with the rats on the coffee table and in the next shot, she is holding the box again. (00:18:35)
The One With Phoebe's Rats - S9-E12
Continuity mistake: At Rachel's birthday party, Phoebe reaches into the shoebox of rats, but straight away in the next shot, her hands are on the lid. (00:14:10)
The One With Phoebe's Rats - S9-E12
Continuity mistake: In the series nine episode with the 'hot' nanny, at the end when Rachel is on the veranda/balcony thing with Gavin, before he says 'I do have feelings for you', the shot is over the shoulder and he has his hand on the wall of the balcony, when the shot switches to the front angle his hand is by his side. (00:20:55)
The One In Barbados, part 2 - S9-E24
Continuity mistake: In the scene where David wants to propose, when Phoebe and David get seated in the restaurant Phoebe puts her bag on the floor to the left of her chair. When there is a wider shot again, it has vanished. (00:25:25)
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.